Canine internal stifle stabilization (CISS) system

ABSTRACT

A Canine internal stifle stabilizing (CISS) system is provided as a three part modular, stifle stabilizing device that can be permanently or temporarily surgically implanted and attached onto the medial side of the distal femur and proximal tibia of quadrupeds. The stabilizing device is centered over the medial aspect of the quadruped stifle joint. The device includes three parts: a femoral component, a tibial component and an articular sliding insert component. The tibial and femoral components are fastened to the medial aspect of the femur and tibia by a varying number of fasteners. The distal end of the femoral component contains a ball and stem. The ball and stem is attached to the femoral component. The proximal tibial component has a rectangular space that accepts and holds the articular sliding insert component, such as by a pressure fit into the rectangular space provided on the proximal tibial component. The articular sliding insert component includes a groove that accepts and holds the ball that is attached to the femoral component. This locks the femoral and tibial components together. Also on the underside of the articular sliding insert component is a flange. In operation, the flange is located between the femoral and tibial components and has a bevelled edge (for example a ten (10) degree bevelled edge) on either side. This bevelled edge allows for a maximum internal and external rotation of the stabilized stifle joint. This device permits normal stifle joint movement in all planes, while continually providing support.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 61/776,735, filed on Mar. 11, 2013 and U.S. ProvisionalPatent Application No. 61/778,324, filed on Mar. 12, 2013, the entiredisclosures of which are expressly incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a method and apparatus veterinaryorthopedic surgical stabilization of an unstable quadruped stifle joint.

2. Related Art

The quadruped stifle is a complex and powerful joint that is stabilizedby four main ligaments: the cranial cruciate, the caudal cruciate, themedial collateral and the lateral collateral. The stifle joint isfurther stabilized by the patella and the tendons associated therewithand the surrounding musculature. These powerful ligaments and tendonsbind the femur and tibia together. Although the structure of the stifleprovides one of the strongest joints of the quadruped body, as inhumans, the stifle joint is also one of the most frequently injuredjoints. The most frequent injury occurs to the cranial cruciateligament. The canine is the most frequently affected quadruped species.The large number of canine cranial cruciate ligament injuries has givenrise to a considerable number of innovative surgical procedures anddevices for attempting to replace the partially or completely torn oravulsed cranial cruciate ligament. A partially, or completely torn,stifle associated ligament or tendon typically results in seriousclinical symptoms such as stifle swelling and inflammation, significantstifle pain, disuse muscular atrophy, radiographic evidence of arthritisand stifle joint instability, resulting in a significantly diminishedability to perform high level, or daily activities relating to mobility.The inevitable long term effects of a damaged and unstable quadrupedstifle joint include significant meniscal and articular cartilage damageto the femur, tibia and patella. This leads to chronic pain anddebilitating degenerative joint disease.

Injuries to any of the ligaments or tendons (including the cranialcruciate ligament) of the quadruped stifle typically require a majorsurgical intervention to repair the damage. Historically and currentlythese attempts at repair have involved both intra-articular andextra-articular repair procedures with varying degrees of success. Morerecently geometric modification of the canine stifle joint has beenadvocated.

As a result, several types of surgical procedures have been developedand are currently in use to attempt to mitigate the instability of thecanine stifle caused by the damaged cranial cruciate ligament and/orother ligaments and tendons. Although primary cranial cruciate ligamentrepair would be ideal, it is unfortunately not a viable option inveterinary medicine. There are several reasons why primary repair is notviable: cranial cruciate injury in quadrupeds is rarely acute, itprogresses over time and the amount of trauma that occurs to the cranialcruciate ligament is usually very severe. As a result the torn ends ofthe cranial cruciate ligament are not of a sufficient length to reattachsuccessfully or have been resorbed to an extent that reattachment is notpossible.

Historically intra-articular stabilization of the cranial cruciatedeficient canine stifle was performed via placement of an autogenousgraft, harvested either from the patella tendon or the tensor fascialata. This method involved harvesting of the graft and then tunnellingthe graft through the stifle joint and attaching so that it mimics thecranial cruciate ligament. This method has fallen out of favor due tothe invasiveness of the surgical procedure required, the inherentweakness of the graft and high rate of failure of the autogenousgrafting material.

All other current techniques involve extracapsular, or outside the jointrepair methods. Numerous terms and techniques are utilized. Oneextra-capsular repair technique utilizes a synthetic nylon (commercialfishing line) or a braided polymer material. These methods bothgenerally ultimately fail. The nylon material cycles, weakens and breaksdue to movement of the stifle joint. The braided polymer material, whilemuch stronger, either breaks, cuts through the bone, or as a result ofbeing braided, becomes infected. These current techniques have beensuccessful in reducing abnormal femoral/tibial movement in a sagittalplane. However, neither of these current extracapsular repair techniquespermits the tibia, in relation to the femur, to internally andexternally rotate as in a normal joint, nor do they permit normalcompression and extension.

Another class of cranial cruciate repair surgery is the geometricmodification of the quadruped stifle joint. There are currently twoaccepted geometric modification procedures: The tibial plateau levelingsurgical osteotomy (TPLO) of the proximal tibia and tibial tuberosityadvancement (TTA). The TPLO procedure involves a full thicknesssemi-circular osteotomy below the proximal tibia. The proximal portionof the tibial bone is then rotated counter-clockwise to decrease thetibial slope and therefore, associated cranial tibial thrust. Therotated bone is fixed in place using a specialized bone plate. The TTAprocedure involves an angled, vertical cut of the tibial tuberosity. Thefreed portion is then advanced and fixed into place using specializedbone plating equipment. Both procedures require a very invasive surgicalprocedure that accomplishes its goal of decreasing cranial tibial thrustby either, transposing or rotating the cut proximal piece of tibia. Thecurrent issues surrounding these repair methods center around therequirement that, either, the caudal cruciate (TPLO) or the centralpatellar tendon (TTA) is required to act as the cranial cruciateligament—a task, neither tissue was designed to do. Other issues withgeometric repair methods include: the limited access of veterinarianscapable of performing the procedures due to the specialized training andexpensive equipment required for both the TPLO and TTA procedures.Perhaps the most alarming concern, with either of these procedures, isthere is no attempt made to limit the internal rotation of the tibiarelative to the femur. This is one of the primary jobs of the quadruped,cranial cruciate ligament. This is particularly important whenconsidering that during certain parts of the stride, the quadrupedstifle joint is non-weight bearing and unsupported. It is during thisnon-weight bearing period that internal rotation of the tibia isunrestricted greatly increasing the risk that additional quadrupedstifle joint trauma can, will, and does, occur at this time.

Other ligament or tendon injuries to the quadruped stifle requiredifferent procedures to repair the damage. Many of these procedures havevarying success rates.

To date no one procedure exists to stabilize an unstable, injured, orfractured quadruped stifle. Accordingly, what is needed in this art is amethod of providing continuous support to the damaged, quadruped stifleduring both non weight bearing and full weight bearing periods. Thissurgical procedure uses a surgically implanted modular quadruped stiflestabilizing device that offers continuous support, while allowing thequadruped stifle to flex, extend, internally and externally rotate, andexpand and compress normally during all phases of the stride.

SUMMARY

A surgical procedure and apparatus is provided for biocompatible,modular surgical stifle stabilization that can be permanently, ortemporarily, implanted on the medial side of the distal femur andproximal tibia to stabilize an unstable, quadruped, stifle joint.

The apparatus provides continuous support to the injured quadrupedstifle, while permitting the quadruped stifle to move in a normal mannerduring all phases of the quadruped stride. The apparatus permits normalflexion and extension and also allows for a normal internal and externalrotation. Stifle joint compression and expansion is also permitted.

This procedure and apparatus is indicated in cranial cruciate rupture,caudal cruciate rupture, medial collateral rupture, lateral collateralrupture, medial patellar luxation, lateral patellar luxation, patellartendon avulsion, patellar fracture, proximal tibial fracture, distalfemoral fracture, stifle disruption and any combination, or degree ofany of the above conditions.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing features of the disclosure will be apparent from thefollowing Detailed Description of the Disclosure, taken in connectionwith the accompanying drawings, in which:

FIG. 1 is a perspective view of the apparatus fully assembled, includingthe femoral component, the tibial component and the articular slidinginsert component;

FIGS. 2A-2D are front, side, perspective and end view, respectively, ofthe femoral component;

FIGS. 3A-3C are side, front and perspective views, respectively, of thetibial component and the articular sliding insert component (FIG. 3C);

FIGS. 4A-4E are detailed perspective, top, cross-sectional, side andbottom views, respectively, of the articular sliding insert component;

FIGS. 5A-5C are perspective, side and bottom views, respectively, of thedetailed femoral ball and stem of the apparatus;

FIG. 6 is another front view of an apparatus fully assembled;

FIG. 7 is a bottom view of the apparatus shown in FIG. 6;

FIGS. 8A-8C are perspective front, and side views of the tibialcomponent shown in FIG. 6, and FIG. 8D is a cross-sectional view takenalong line D-D in FIG. 8C;

FIG. 9 is a side view of a ball and stem;

FIG. 10 is a perspective view of the ball and stem shown in FIG. 9attached to the femoral component;

FIGS. 11A-11C are perspective, front and side views of the tibialcomponent;

FIG. 12 is a perspective view of the intermediate component positionedto receive the ball attached to the femoral component;

FIG. 13 is a perspective view of the ball positioned in the intermediatecomponent;

FIG. 14 is a perspective view of the tibial component positioned toreceive the intermediate component; and

FIG. 15 is another perspective view of a fully assembled apparatus.

DETAILED DESCRIPTION

A modular surgically implanted apparatus is disclosed that can be usedin canine, feline and other quadruped animal species, both domestic andexotic, to stabilize an unstable stifle joint that may be due to anynumber of causes, for example, soft tissue or hard tissue injury of thestifle ligaments, tendons and their attachments and surroundingstructures. The system works for primary treatment for a partial orcomplete cranial cruciate ligament injury or avulsion, a partial orcomplete caudal cruciate ligament injury or avulsion, a partial orcomplete medial collateral ligament injury or avulsion, a partial orcomplete lateral collateral ligament injury or avulsion, a congenital ortraumatic medial patellar luxation or avulsion, a congenital ortraumatic lateral patellar luxation or avulsion, a patellar fracture, orany combination of, or all of the above.

The Canine Internal Stifle Stabilizing (CISS) system provides continuoussupport and allows for the normal extension (e.g., 160 degrees) andflexion (e.g., 40 degrees) range of motion of the stifle joint, tibia inrelation to the femur, during weight bearing and non-weight bearingperiods. In the canine patient, the angle of the stifle is measured fromthe lateral side. It is the angle formed by an intersecting linebisecting the center of the femur and tibia. In the normal caninepatient, the stifle range of motion is approximately from one hundredand sixty (160) degrees in full extension to forty (40) degrees in fullflexion. The CISS system provides for normal internal (e.g., 25 degreesas measure at the foot) and external (e.g., 15 degrees as measured atthe foot) tibial rotation. Tibial rotation is measured as the amount ofinward or outward twisting of the tibia relative to the femur. In thenormal canine patient the normal maximum internal tibial rotation,relative to the femur, is generally about twenty-five (25) degreesmeasured at the foot. The normal maximum external rotation, relative tothe femur, is generally about fifteen (15) degrees measured at the foot.The proximal tibia rotates about 10 degrees in either external orinternal rotation.

Referring to FIG. 1, the CISS system is shown as a surgically implanted,modular stifle stabilizing device comprising three components: thefemoral component 10, the tibial component 40, and the articular slidinginsert component 60. Each stabilizing component can be a separatelymanufactured component that is interconnected to the next component.These connections between the components allow the individual componentsto maintain the normal range of motion and normal external and internalrotation of the canine, feline or other quadruped stifle, whilecontinuously stabilizing the stifle joint.

Referring to FIGS. 2A-2D, the femoral component 10 is a form fitting,generally “L” shaped, curved component that conforms and can bepermanently, or temporarily attached to the contour of the medial thirdof the distal femur. The femoral component 10 includes a leg portion 12and a bottom portion 14, which can be positioned at an angle Θ withrespect to leg portion 12 as shown in FIG. 2B. The leg portion 12 canhave front and back generally planar faces and opposing, generallyplanar edges. At the distal end, the edges can terminate in a roundeddistal edge. The bottom portion 14 includes front and back generallyplanar faces and an edge that defines a bulbous shape. The femoralcomponent 10 can be made from a number of acceptable, biocompatible,implantable materials. These materials include, but are not limited to,316MVL stainless steel, titanium or UHMWPE. Exposed edges of the femoralcomponent 10 can be rounded and smooth. The length of the femoralcomponent 10 can vary with the size of patient. However, the size rangeis approximately 30-60 mm in length, and approximately 10-35 mm inwidth. Similarly, the thickness of the femoral component 10 can varywith the size of the patient. However, generally the thickness is in therange of about 2-3 mm. The dimensions of the femoral component 10 canvary with the different sizes that are produced and can be based whollyor in part on the body weight of the patient.

The femoral component 10 contains attachment holes in leg 12 such as two(2) to three (3) permanent attachment holes, 12 a, 12 b and 12 c. Theseholes can be aligned and extend through the front and back generallyplanar faces. The diameter of these holes can vary such that they willaccept the appropriate sized screw, or other fastener. For example, theholes 12 a, 12 b and 12 c could be 3.5 mm in diameter, to allow for theplacement of a 3.5 mm cortical bone screw. The holes 12 a, 12 b and 12 ccan be sized to have a sufficient diameter such that the head of thescrew, such as a 3.5 mm cortical screw, fits flush with the femoralcomponent 10. Other sized bone screws, such as 2.0 mm, 2.7 mm, or 3.5 mmcortical bone screws can also be used, and the holes 12 a, 12 b and 12 ccould be sized accordingly. The distal end of the femoral component 10can be contoured to be elevated away from the bone of the distal femurso as not to impede femoral soft tissues. Accordingly, a clearance of1-2 mm can be provided.

As shown in FIGS. 2C and 2D, a ball 20 and stem 22 are located on thebottom portion 14 of the femoral component 10. The stem 22 is receivedby aperture 16, and the ball extends outward from the outer surface ofthe femoral component 10 at 90 degrees. The ball 20 and stem 22 can beformed separately and joined together or they can be of a unitaryconstruction. The stem 22 can be pressure fit into an aperture 16 in thebottom portion 14. Other methods of attachment, however, can beemployed. For example, aperture 16 and stem 22 could be threadablyengaged. Similarly, stem 22 could be threadably engaged with ball 20.The shape of ball 20 can be varied as desired provided it caninterlocked with the tibial component 40, such as by way of insertcomponent 60, as will be described. This forms the articulation point onthe femoral component 10. The ball 20 engages the articular slidinginsert component which is in turn inserted into the tibial component, aswill be described. The ball 20 permits the stifle joint complete andcontinuous support during both full extension and full flexion fromapproximately one hundred and sixty (160) degrees (full extension) toapproximately forty (40) degrees (full flexion).

Referring to FIGS. 3A-3C, the tibial component 40 conforms to thecontours of the proximal medial tibia. The tibial component 40 is acurved having a first proximal planar portion 42, a first bend 44, asecond central planar portion 46, a second bend 47 and a third distalplanar portion 48. The tibial component 40 can be made from a number ofacceptable, biocompatible, implantable materials. These materialsinclude, but are not limited to, 316MVL stainless steel, titanium orUHMWPE. Exposed edges of the tibial component 40 can be rounded andsmooth. The length of the tibial component 40 can vary with the size ofpatient. However, the size range is approximately 30-60 mm in length,and approximately 10-35 mm in width. The thickness of the tibialcomponent 40 can also vary with the size of the patient. However,generally the thickness is in the range of about 2-3 mm. The secondcentral planar portion 44 and the distal planar portion 48 include frontand back general planar faces and opposing generally planar edges. Atthe distal edge, the edges terminate in a rounded distal edge. Thetibial component 40 contains attachment holes in third distal planarportion 48, such as two to three permanent holes 48 a, 48 b and 48 c,for attachment to the tibia. The diameter of these holes can be sizedsuch that they will accept the appropriate sized screw, or otherfastener. For example, the holes 48 a, 48 b and 48 c could be 3.5 mm indiameter, to allow for the placement of a 3.5 mm cortical bone screw.The holes 48 a, 48 b and 48 c can be sized to have a sufficient diametersuch that the head of the screw, such as a 3.5 mm cortical screw, willfit flush with the tibial component 40. Other sizes, such as 2.0 mm, 2.7mm, or 3.5 mm cortical bone screws can also be used, and the holes 48 a,48 b and 48 c can be sized accordingly. The attachment holes can besized such that they will accept the appropriate sized screw and so thatthe screw is flush when implanted. The proximal part of the tibialcomponent 40 can rise about 1-2 mm off the medial surface of theproximal tibia to allow for the clearance of the soft tissues of theproximal stifle. The first proximal planar portion 42 of the tibialcomponent 40 has wider edge to edge front and back generally planarfaces and includes a slot, such as a rectangular slot 50, extendingthrough the front and back generally planar faces. This rectangular slot50 on the tibial component 40 receives, such as by a pressure fitattachment, the articular sliding insert component 60. The rectangularslot 50 allows the articular sliding insert component to be firmly heldin place. Other ways of connecting the insert component 60 to the tibiacomponent 40 and the femoral component 10 to the insert component 60 areconsidered to be with the scope of this disclosure.

Referring to FIGS. 4A-4E, the articular sliding insert component 60, orintermediate component comprises a rectangular-shaped component thatconforms to the rectangular opening 50 of the tibial component 40. Thearticular sliding insert component 60 can be made of a biocompatible,surgically implantable material that preferably has good wearcharacteristics, is inert and carries a low coefficient of friction. Assuch, the insert component could be made of a plastic such as a UltraHigh Molecular Weight Polyethelene (UHMWPE) material. The articularsliding insert component 60 fits into and is received by anappropriately sized rectangular slot 50 of the proximal tibial component40. The insert 60 could be secured in the tibial component 40 by apressure fit or otherwise. The articular sliding insert component 60 hasa top 62 and side walls 64 surrounding a central channel, and includesangled flange extensions 66 extending outwardly from the lower ends ofsidewalls 64. The flanges 66 extend to and contact the tibial component40 when inserted into slot 50. As shown in FIG. 4C, the central channelis cylindrical shaped, and can be open at one or both of the forward andrear sides 68 and 69 along the lower side. The articular central cavityof sliding insert component 60 is configured to accept and interlockwith the circular ball 20 attached to the femoral component 10. Thisallows the femoral ball 20 to be captured and held in place during allphases of the stride. One end of the insert could have a wall thatcloses one end of the cavity. The tibial component, where attached tothe insert, closes off one or both ends of the cavity to prevent theball from escaping the cavity. The flanges 66 provide continualseparation of both the tibial and femoral components. This extension canbe angled to allow approximately ten (10) degrees of internal andexternal rotation of the tibial component 40. The rotation is limited toapproximately ten (10) degrees of internal rotation and ten (10) degreesof external rotation by the angled flanges 66. The relationship betweenthe tibial component 40 and the articular sliding insert component 60allows for the independent internal and external rotation of the tibiawhile continuously providing support for the stifle throughout thenormal flexion and extension of the quadruped stifle joint. Thearticular sliding insert component 60 allows for the internal andexternal rotation at any phase of extension or flexion.

The cylindrical shaped central channel is sized and shaped to correspondwith the size and shape of the ball attached to the femoral component.As such, the connection between the cylindrical channel and the ballcreates a ball and socket type joint that allows for rotational andpivotal or swivel movement of the ball with respect to the channel, andaccordingly, allows for such movement of the femur with respect to theintermediate component and the tibial component. Further, the channelallows for the ball to slide from end to end along the length of thechannel thereby providing for additional translational movement of theball with respect to the channel, and accordingly, allows for suchmovement of the femoral component with respect to the intermediatecomponent and the tibial component. When assembled, the insert componentcan be maintained in position with respect to the tibial component byvirtue of the tibial component fitting between the lower flanges of theintermediate component and corresponding shoulders positioned in facingrelationship thereto. Although the intermediate component and the spacetherefore in the tibial component has been shown and described as havinga rectangular shape, the shape could take on any suitable form.

FIGS. 5A-5C show views of the ball 20 and stem 22 that connects with thefemoral component 10 and the articular sliding component 60. Like thefemoral and tibial components, the ball and stem can be made of abiocompatible material.

FIG. 6 is another view of a fully assembled apparatus showing thefemoral component 110, the tibial component 140 and the insert component160. FIG. 7 is a bottom view thereof.

FIG. 8A is another perspective view of the femoral component 110. FIG.8B is a front view of the femoral component showing the leg portion 112and bottom portion 114. FIG. 8C is a side view of the femoral componentshowing angle Θ, leg portion 112 and bottom portion 114. FIG. 8D is across-sectional view taken along line D-D on FIG. 8B showing an aperture112B that could be partially threaded at one area 112BB while having aunthreaded recessed area 112BA. Any suitably configured aperture couldbe used in the femoral or tibial component. FIG. 9 shows a side view ofthe ball 120 and stem 122.

As shown in FIG. 10 the ball 120 is attached to the femoral component110 at the bottom portion 114 by inserting the stem of the ball into theaperture in the femoral component.

FIG. 11A is another perspective view of the tibial component 140. FIG.11B is a front view of the tibial component 140 showing the slot 150 andapertures 148 a, 148 b, and 148 c. The apertures can be formed inaccordance with the apertures described with respect to the femoralcomponent. FIG. 11C is a side view of the tibial component showing afirst proximal planar portion 142, a first bend 144, a second centralplanar potion 146, a second bend 147, and a third distal planar portion148. FIG. 12 is a perspective view showing the insert component 160positioned to slide over and engage with ball 120 attached to thefemoral component 110. FIG. 13 is a perspective view showing the ballattached to the femoral component engaged within the insert component160. FIG. 14 is a perspective view of the tibial component 140positioned to receive the insert component 160 into rectangular slot150. FIG. 15 is a perspective view showing the fully engaged device.

The components of the apparatus, such as the femoral and tibialcomponents, or plates, can be either machined from a solid piece ofmaterial or they can be stamped using a stamping tool and then finishedwith machining operations, as is known in the art. Similarly, the insertcomponent can be created by molding and/or machining.

While the components of the apparatus could be sold separately andassembled by a user such as a surgeon, the apparatus will generally besold preassembled as a unit. The preassembled apparatus will beinstalled in an animal by attaching the femoral plate and tibial plate,respectively, to the femur and tibia of an animal.

A modular device, surgically implanted on a temporary or permanent basisthat stabilizes a quadruped stifle joint that is unstable due to cranialcruciate ligament rupture, or avulsion that is either partial orcomplete.

A modular device, surgically implanted on a temporary or permanent basisthat stabilizes a quadruped stifle joint that is unstable due to caudalcruciate ligament rupture, or avulsion that is either partial orcomplete.

A modular device, surgically implanted on a temporary or permanent basisthat stabilizes a quadruped stifle joint that is unstable due to medialcollateral ligament rupture, or avulsion that is either partial orcomplete.

A modular device, surgically implanted on a temporary or permanent basisthat stabilizes a quadruped stifle joint that is unstable due to lateralcollateral ligament rupture, or avulsion that is either partial orcomplete.

A modular device surgically implanted on a temporary or permanent basisthat stabilizes a quadruped stifle joint that has suffered a traumatic,or congenital medial patellar luxation.

A modular device, surgically implanted on a temporary or permanent basisthat stabilizes a quadruped stifle that has suffered a traumatic orcongenital lateral patellar luxation.

A modular device, surgically implanted on a temporary basis thatstabilizes a quadruped stifle joint that has suffered a traumatic orcongenital patellar tendon avulsion, or patellar fracture.

A modular device, surgically implanted on a temporary or permanent basisthat stabilizes a quadruped stifle that has suffered a traumaticfracture to either the distal femur, or proximal tibia.

A modular device, surgically implanted on a temporary or permanent basisthat stabilizes a quadruped stifle that has suffered any combination, orall of the above conditions.

The invention claimed is:
 1. A stifle stabilization system, comprising:a femoral component having a leg portion and bottom portion, the bottomportion including an interconnected ball and stem protruding therefrom;an articular sliding insert component defining a cylindrical channelcorresponding in size and shape to the ball; and a tibial componenthaving a first proximal planar portion defining a slot, the slot beingof corresponding and complementary shape to sidewalls of the articularsliding insert component to receive the articular sliding insertcomponent therein in a pressure fit engagement, wherein, when thechannel receives the ball and the articular sliding insert component isreceived in the slot of the tibial component, the tibial componentcloses an end of the channel to retain the ball in the channel, and thetibial component is interlocked with the femoral component withtranslational and rotational movement therebetween.
 2. The system ofclaim 1, wherein the system, when surgically implanted, stabilizes anunstable quadruped stifle joint during all phases of a stride and allowsfor normal stifle flexion, extension, internal rotation, externalrotation, and joint compression.
 3. The system of claim 1, wherein theleg portion of the femoral component includes attachment holes forattachment to a femur.
 4. The system of claim 1, wherein the femoralcomponent conforms and is permanently attached to a contour of a medialthird of a distal femur.
 5. The system of claim 1, wherein the femoralcomponent conforms and is temporarily attached to a contour of a medialthird of a distal femur.
 6. The system of claim 1, wherein the legportion and bottom portion form an angle with respect to one another. 7.The system of claim 1, wherein the bottom portion of the femoralcomponent includes an aperture, and the stem is retained within theaperture.
 8. The system of claim 7, wherein the stem is pressure fitinto the aperture.
 9. The system of claim 1, wherein the tibialcomponent conforms and is attached to contours of a proximal medialtibia.
 10. The system of claim 1, wherein the tibial component has afirst proximal planar portion, a second central planar portion, and athird distal planar portion, with a first bend between the firstproximal planar portion and second central planar portion, and a secondbend between the second central planar portion and third distal planarportion.
 11. The system of claim 10, wherein the third distal planarportion of the tibial component contains attachment holes for attachmentto a tibia.
 12. The system of claim 1, wherein the articular slidinginsert component further comprises flange extensions protrudingoutwardly from a lower portion of sidewalls.
 13. The system of claim 1,wherein the ball of the femoral component is slidable along a length ofthe channel of the articular sliding component when the ball is retainedin the channel.
 14. A stifle stabilization system, comprising: a femoralcomponent having one or more attachment holes and an interconnected balland stem protruding therefrom; an articular sliding insert componentdefining a cylindrical channel corresponding in size and shape to theball; and a tibial component having one or more attachment holes anddefining a slot, the slot being of corresponding and complementary shapeto sidewalls of the articular sliding insert component to receive thearticular sliding insert component therein in a pressure fit engagement.15. The system of claim 14, wherein the system, when surgicallyimplanted, stabilizes an unstable quadruped stifle joint during allphases of a stride and allows for normal stifle flexion, extension,internal rotation, external rotation, and joint compression.
 16. Thesystem of claim 14, wherein the leg portion of the femoral componentincludes attachment holes for attachment to a femur.
 17. The system ofclaim 14, wherein the femoral component conforms to contours of a femur.18. The system of claim 14, wherein the leg portion and bottom portionform an angle with respect to one another.
 19. The system of claim 14,wherein the tibial component conforms to contours of a tibia.
 20. Thesystem of claim 14, wherein the tibial component has a first proximalplanar portion, a second central planar portion, and a third distalplanar portion, with a first bend between the first proximal planarportion and second central planar portion, and a second bend between thesecond central planar portion and third distal planar portion.
 21. Thesystem of claim 20, wherein the third distal planar portion of thetibial component contains attachment holes for attachment to a tibia.22. The system of claim 14, wherein the cylindrical channel of thearticular sliding insert component is sized and shaped to receive theball of the femoral component in slidable engagement along a length ofthe channel.